So nice, they named it twice!
The European Otter (Lutra lutra) is also called the Common Otter, because it is so widely distributed throughout Europe and Asia that it is considered to be a “typical” example of a river otter. They can, theoretically, live in any body of water within their range as long as it’s not polluted and has a good supply of food. They even venture into saltwater along the coasts, although in order to do that they need access to freshwater to clean their fur. For this reason, they are not considered to be a “sea otter.” They are hardy and versatile creatures.
European Otters typically have brown coats that are lighter on their bellies. They have an elongated body and thick, powerful tails. They are able to close their ears and nostrils when they submerge (wish I could do that), and their dense fur provides insulation for them by trapping a layer of air within the coat. Adult European Otters can grow up to 37 inches (95 cm) in body length, with a tail of up to 18 inches (45 cm). Females are usually shorter in length than males. They weigh around 26 pounds (12 kg), though an unverified specimen was reported to have weighed 53 pounds (24 kg).
The diet of European Otters is mainly different kinds of fish, which vary depending on the otter’s range. They diversify when necessary, such as during the winter or when they live in cold climates where there are fewer fish to be had. In those cases, they will eat small mammals, birds, amphibians, crustaceans, and insects. Young otters stay with their mother for up to 18 months, until they become competent fishers themselves. In order to teach them these skills, mother otters will capture fish alive and set the free next to their offspring, so that they can practice.
European Otters can breed at any time of the year, and mating occurs in the water. They are solitary creatures and very territorial, but only against other otters of the same sex. This means that the territories of males and females can overlap. Territories are smaller closer to the coasts, where there’s more room to forage, and larger in inland rivers, where they need to claim a larger area in order to have enough food to sustain themselves. Female European Otters will give birth to a litter of one to four pups after a gestation period of approximately 60 days.
Despite being the most widely-distributed species of otter in the world, its population has declined in some areas within its overall range. The reason for this is primarily pollution and pesticides such as PCBs, although hunting and habitat destruction have also contributed. Conservation efforts for vulnerable populations have included captive breeding and reintroduction efforts, as well as habitat protection. In some cases of habitat protection, the otters have naturally recolonized the areas.
Source for all images used in this post.